SwiftExpression

Swift Expression is a Regex framework built with Swift to make it easier to work with NSRegularExpression. The framework provides low overhead to work with pattern matching.

Motivation

There is not a native Regex implemenation in Swift or Objective-C as there is in other languages such as javascript or ruby. This framework’s goal is to make it easier to work with Regex in a "Swifty" way. The framework is built on NSRegularExpression with just easy to call methods and easy objects to work with. To feel as native as possible the Swift String type has been extended with new methods for Regex.

Requirements

Xcode 8

Swift 3

iOS 8.0+

Code Example

Create a Regex object

A Regex can be created multiple ways.

Failable Initializer

if let regex = Regex("^\d") {
// use regex object
}

Prefix operator

The prefix operator is used as a way to initialize a regex struct and is built on the failable initalizer.

if let regex = <>"^\d" {
// use regex object
}

Infix operator

Use the custom infix to check for a match.

let str = "333-aa-bb"
let regexPatternStr = "^\d"
// string to search in on left hand side, regex pattern in string format on right hand side
if str ~= regexPatternStr {
// a match is in the string continue processing
} else {
// failed to find a single match in string
}

String extension methods

Match

let match = str.match(regex) // Returns a Regex.Match struct
match.components // Returns a collection of tuples that are the substring match and range of the match [(String, Range<String.Index>)]
match.subStrings() // Returns a collection of the substring matches [String]
match.ranges() // Returns a collection of ranges of the matches [Range<String.Index>]